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1.
Front Immunol ; 13: 834988, 2022.
Article in English | MEDLINE | ID: covidwho-1817941

ABSTRACT

Patients with COVID-19 present with a wide variety of clinical manifestations. Thromboembolic events constitute a significant cause of morbidity and mortality in patients infected with SARS-CoV-2. Severe COVID-19 has been associated with hyperinflammation and pre-existing cardiovascular disease. Platelets are important mediators and sensors of inflammation and are directly affected by cardiovascular stressors. In this report, we found that platelets from severely ill, hospitalized COVID-19 patients exhibited higher basal levels of activation measured by P-selectin surface expression and had poor functional reserve upon in vitro stimulation. To investigate this question in more detail, we developed an assay to assess the capacity of plasma from COVID-19 patients to activate platelets from healthy donors. Platelet activation was a common feature of plasma from COVID-19 patients and correlated with key measures of clinical outcome including kidney and liver injury, and APACHEIII scores. Further, we identified ferritin as a pivotal clinical marker associated with platelet hyperactivation. The COVID-19 plasma-mediated effect on control platelets was highest for patients that subsequently developed inpatient thrombotic events. Proteomic analysis of plasma from COVID-19 patients identified key mediators of inflammation and cardiovascular disease that positively correlated with in vitro platelet activation. Mechanistically, blocking the signaling of the FcγRIIa-Syk and C5a-C5aR pathways on platelets, using antibody-mediated neutralization, IgG depletion or the Syk inhibitor fostamatinib, reversed this hyperactivity driven by COVID-19 plasma and prevented platelet aggregation in endothelial microfluidic chamber conditions. These data identified these potentially actionable pathways as central for platelet activation and/or vascular complications and clinical outcomes in COVID-19 patients. In conclusion, we reveal a key role of platelet-mediated immunothrombosis in COVID-19 and identify distinct, clinically relevant, targetable signaling pathways that mediate this effect.


Subject(s)
Blood Platelets/immunology , COVID-19/immunology , Complement C5a/metabolism , Receptor, Anaphylatoxin C5a/metabolism , Receptors, IgG/metabolism , SARS-CoV-2/physiology , Thromboembolism/immunology , Adult , Aminopyridines/pharmacology , Cells, Cultured , Female , Hospitalization , Humans , Male , Morpholines/pharmacology , Platelet Activation , Pyrimidines/pharmacology , Severity of Illness Index , Signal Transduction , Syk Kinase/antagonists & inhibitors
2.
Cell ; 185(11): 1875-1887.e8, 2022 05 26.
Article in English | MEDLINE | ID: covidwho-1778028

ABSTRACT

We examined antibody and memory B cell responses longitudinally for ∼9-10 months after primary 2-dose SARS-CoV-2 mRNA vaccination and 3 months after a 3rd dose. Antibody decay stabilized between 6 and 9 months, and antibody quality continued to improve for at least 9 months after 2-dose vaccination. Spike- and RBD-specific memory B cells remained durable over time, and 40%-50% of RBD-specific memory B cells simultaneously bound the Alpha, Beta, Delta, and Omicron variants. Omicron-binding memory B cells were efficiently reactivated by a 3rd dose of wild-type vaccine and correlated with the corresponding increase in neutralizing antibody titers. In contrast, pre-3rd dose antibody titers inversely correlated with the fold-change of antibody boosting, suggesting that high levels of circulating antibodies may limit the added protection afforded by repeat short interval boosting. These data provide insight into the quantity and quality of mRNA-vaccine-induced immunity over time through 3 or more antigen exposures.


Subject(s)
COVID-19 Vaccines , COVID-19 , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , Humans , RNA, Messenger , SARS-CoV-2 , Vaccines, Synthetic , mRNA Vaccines
4.
Cell ; 185(6): 1008-1024.e15, 2022 03 17.
Article in English | MEDLINE | ID: covidwho-1664732

ABSTRACT

Vaccine-mediated immunity often relies on the generation of protective antibodies and memory B cells, which commonly stem from germinal center (GC) reactions. An in-depth comparison of the GC responses elicited by SARS-CoV-2 mRNA vaccines in healthy and immunocompromised individuals has not yet been performed due to the challenge of directly probing human lymph nodes. Herein, through a fine-needle aspiration-based approach, we profiled the immune responses to SARS-CoV-2 mRNA vaccines in lymph nodes of healthy individuals and kidney transplant recipients (KTXs). We found that, unlike healthy subjects, KTXs presented deeply blunted SARS-CoV-2-specific GC B cell responses coupled with severely hindered T follicular helper cell, SARS-CoV-2 receptor binding domain-specific memory B cell, and neutralizing antibody responses. KTXs also displayed reduced SARS-CoV-2-specific CD4 and CD8 T cell frequencies. Broadly, these data indicate impaired GC-derived immunity in immunocompromised individuals and suggest a GC origin for certain humoral and memory B cell responses following mRNA vaccination.

5.
Nat Med ; 27(11): 1990-2001, 2021 11.
Article in English | MEDLINE | ID: covidwho-1526094

ABSTRACT

SARS-CoV-2 messenger RNA vaccination in healthy individuals generates immune protection against COVID-19. However, little is known about SARS-CoV-2 mRNA vaccine-induced responses in immunosuppressed patients. We investigated induction of antigen-specific antibody, B cell and T cell responses longitudinally in patients with multiple sclerosis (MS) on anti-CD20 antibody monotherapy (n = 20) compared with healthy controls (n = 10) after BNT162b2 or mRNA-1273 mRNA vaccination. Treatment with anti-CD20 monoclonal antibody (aCD20) significantly reduced spike-specific and receptor-binding domain (RBD)-specific antibody and memory B cell responses in most patients, an effect ameliorated with longer duration from last aCD20 treatment and extent of B cell reconstitution. By contrast, all patients with MS treated with aCD20 generated antigen-specific CD4 and CD8 T cell responses after vaccination. Treatment with aCD20 skewed responses, compromising circulating follicular helper T (TFH) cell responses and augmenting CD8 T cell induction, while preserving type 1 helper T (TH1) cell priming. Patients with MS treated with aCD20 lacking anti-RBD IgG had the most severe defect in circulating TFH responses and more robust CD8 T cell responses. These data define the nature of the SARS-CoV-2 vaccine-induced immune landscape in aCD20-treated patients and provide insights into coordinated mRNA vaccine-induced immune responses in humans. Our findings have implications for clinical decision-making and public health policy for immunosuppressed patients including those treated with aCD20.


Subject(s)
COVID-19 Vaccines/therapeutic use , Multiple Sclerosis/immunology , Multiple Sclerosis/therapy , SARS-CoV-2/immunology , Animals , Antibodies, Monoclonal/therapeutic use , Antibodies, Viral/analysis , Antibodies, Viral/blood , Antigens, CD20/immunology , COVID-19/prevention & control , Case-Control Studies , Chlorocebus aethiops , HEK293 Cells , Humans , Immunity, Cellular , Immunity, Humoral/drug effects , Immunity, Humoral/physiology , Immunotherapy/methods , Longitudinal Studies , Multiple Sclerosis/blood , RNA, Messenger/immunology , RNA, Viral/immunology , Rituximab/pharmacology , Rituximab/therapeutic use , SARS-CoV-2/genetics , Vaccination , Vero Cells
6.
Science ; 374(6572): abm0829, 2021 Dec 03.
Article in English | MEDLINE | ID: covidwho-1467659

ABSTRACT

The durability of immune memory after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccination remains unclear. In this study, we longitudinally profiled vaccine responses in SARS-CoV-2­naïve and ­recovered individuals for 6 months after vaccination. Antibodies declined from peak levels but remained detectable in most subjects at 6 months. By contrast, mRNA vaccines generated functional memory B cells that increased from 3 to 6 months postvaccination, with the majority of these cells cross-binding the Alpha, Beta, and Delta variants. mRNA vaccination further induced antigen-specific CD4+ and CD8+ T cells, and early CD4+ T cell responses correlated with long-term humoral immunity. Recall responses to vaccination in individuals with preexisting immunity primarily increased antibody levels without substantially altering antibody decay rates. Together, these findings demonstrate robust cellular immune memory to SARS-CoV-2 and its variants for at least 6 months after mRNA vaccination.


Subject(s)
COVID-19 Vaccines/immunology , Immunologic Memory , SARS-CoV-2/genetics , SARS-CoV-2/immunology , mRNA Vaccines/immunology , Humans
7.
Immunity ; 54(9): 2133-2142.e3, 2021 09 14.
Article in English | MEDLINE | ID: covidwho-1433401

ABSTRACT

SARS-CoV-2 mRNA vaccines have shown remarkable clinical efficacy, but questions remain about the nature and kinetics of T cell priming. We performed longitudinal antigen-specific T cell analyses on healthy SARS-CoV-2-naive and recovered individuals prior to and following mRNA prime and boost vaccination. Vaccination induced rapid antigen-specific CD4+ T cell responses in naive subjects after the first dose, whereas CD8+ T cell responses developed gradually and were variable in magnitude. Vaccine-induced Th1 and Tfh cell responses following the first dose correlated with post-boost CD8+ T cells and neutralizing antibodies, respectively. Integrated analysis revealed coordinated immune responses with distinct trajectories in SARS-CoV-2-naive and recovered individuals. Last, whereas booster vaccination improved T cell responses in SARS-CoV-2-naive subjects, the second dose had little effect in SARS-CoV-2-recovered individuals. These findings highlight the role of rapidly primed CD4+ T cells in coordinating responses to the second vaccine dose in SARS-CoV-2-naive individuals.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , SARS-CoV-2/physiology , Th1 Cells/immunology , Adult , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Antigens, CD/metabolism , Antigens, Differentiation, T-Lymphocyte/metabolism , Female , Humans , Immunity, Cellular , Immunity, Humoral , Immunization, Secondary , Immunologic Memory , Lectins, C-Type/metabolism , Lymphocyte Activation , Male , Middle Aged , Peptides/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccination , Young Adult
8.
Nat Med ; 27(11): 1990-2001, 2021 11.
Article in English | MEDLINE | ID: covidwho-1410406

ABSTRACT

SARS-CoV-2 messenger RNA vaccination in healthy individuals generates immune protection against COVID-19. However, little is known about SARS-CoV-2 mRNA vaccine-induced responses in immunosuppressed patients. We investigated induction of antigen-specific antibody, B cell and T cell responses longitudinally in patients with multiple sclerosis (MS) on anti-CD20 antibody monotherapy (n = 20) compared with healthy controls (n = 10) after BNT162b2 or mRNA-1273 mRNA vaccination. Treatment with anti-CD20 monoclonal antibody (aCD20) significantly reduced spike-specific and receptor-binding domain (RBD)-specific antibody and memory B cell responses in most patients, an effect ameliorated with longer duration from last aCD20 treatment and extent of B cell reconstitution. By contrast, all patients with MS treated with aCD20 generated antigen-specific CD4 and CD8 T cell responses after vaccination. Treatment with aCD20 skewed responses, compromising circulating follicular helper T (TFH) cell responses and augmenting CD8 T cell induction, while preserving type 1 helper T (TH1) cell priming. Patients with MS treated with aCD20 lacking anti-RBD IgG had the most severe defect in circulating TFH responses and more robust CD8 T cell responses. These data define the nature of the SARS-CoV-2 vaccine-induced immune landscape in aCD20-treated patients and provide insights into coordinated mRNA vaccine-induced immune responses in humans. Our findings have implications for clinical decision-making and public health policy for immunosuppressed patients including those treated with aCD20.


Subject(s)
COVID-19 Vaccines/therapeutic use , Multiple Sclerosis/immunology , Multiple Sclerosis/therapy , SARS-CoV-2/immunology , Animals , Antibodies, Monoclonal/therapeutic use , Antibodies, Viral/analysis , Antibodies, Viral/blood , Antigens, CD20/immunology , COVID-19/prevention & control , Case-Control Studies , Chlorocebus aethiops , HEK293 Cells , Humans , Immunity, Cellular , Immunity, Humoral/drug effects , Immunity, Humoral/physiology , Immunotherapy/methods , Longitudinal Studies , Multiple Sclerosis/blood , RNA, Messenger/immunology , RNA, Viral/immunology , Rituximab/pharmacology , Rituximab/therapeutic use , SARS-CoV-2/genetics , Vaccination , Vero Cells
9.
Sci Immunol ; 6(58)2021 04 15.
Article in English | MEDLINE | ID: covidwho-1349998

ABSTRACT

Novel mRNA vaccines for SARS-CoV-2 have been authorized for emergency use. Despite their efficacy in clinical trials, data on mRNA vaccine-induced immune responses are mostly limited to serological analyses. Here, we interrogated antibody and antigen-specific memory B cells over time in 33 SARS-CoV-2 naïve and 11 SARS-CoV-2 recovered subjects. SARS-CoV-2 naïve individuals required both vaccine doses for optimal increases in antibodies, particularly for neutralizing titers against the B.1.351 variant. Memory B cells specific for full-length spike protein and the spike receptor binding domain (RBD) were also efficiently primed by mRNA vaccination and detectable in all SARS-CoV-2 naive subjects after the second vaccine dose, though the memory B cell response declined slightly with age. In SARS-CoV-2 recovered individuals, antibody and memory B cell responses were significantly boosted after the first vaccine dose; however, there was no increase in circulating antibodies, neutralizing titers, or antigen-specific memory B cells after the second dose. This robust boosting after the first vaccine dose strongly correlated with levels of pre-existing memory B cells in recovered individuals, identifying a key role for memory B cells in mounting recall responses to SARS-CoV-2 antigens. Together, our data demonstrated robust serological and cellular priming by mRNA vaccines and revealed distinct responses based on prior SARS-CoV-2 exposure, whereby COVID-19 recovered subjects may only require a single vaccine dose to achieve peak antibody and memory B cell responses. These findings also highlight the utility of defining cellular responses in addition to serologies and may inform SARS-CoV-2 vaccine distribution in a resource-limited setting.


Subject(s)
Antibodies, Viral/immunology , B-Lymphocytes/immunology , COVID-19 Vaccines , COVID-19/immunology , SARS-CoV-2/immunology , Vaccines, Synthetic , Adult , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Female , Humans , Male , Middle Aged , RNA, Messenger , Spike Glycoprotein, Coronavirus/immunology , Vaccination , Young Adult
10.
Am J Prev Med ; 61(1): 13-19, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1157096

ABSTRACT

INTRODUCTION: In response to the COVID-19 pandemic, governments have implemented social distancing measures to slow viral transmission. This work aims to determine the extent to which socioeconomic and political conditions have shaped community-level distancing behaviors during the COVID-19 pandemic, especially how these dynamics have evolved over time. METHODS: This study used daily data on physical distancing from 15‒17 million cell phone users in 3,037 U.S. counties. County-level changes in the average distance traveled per person were estimated relative to prepandemic weeks as a proxy for physical distancing. Pooled ordinary least squares regressions estimated the association between physical distancing and a variety of county-level demographic, socioeconomic, and political characteristics by week from March 9, 2020 to January 17, 2021. Data were collected until January 2021, at which point the analyses were finalized. RESULTS: Lower per capita income and greater Republican orientation were associated with significantly reduced physical distancing throughout nearly all the study period. These associations persisted after adjusting for a variety of county-level demographic and socioeconomic characteristics. Other county-level characteristics, such as the shares of Black and Hispanic residents, were associated with reduced distancing at various points during the study period. CONCLUSIONS: These results highlight the importance of dynamic socioeconomic and political gradients in preventive behavior and imply the need for nimble policy responses.


Subject(s)
COVID-19 , Humans , Pandemics , Physical Distancing , SARS-CoV-2 , Socioeconomic Factors
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